<!--
	怎再依照官方文档写一 多折线图
-->
<template>
	<v-chart :force-fit="true" :height="height" :data="data" :scale="scale" class="v-chart">
	  	<v-tooltip />
	  	<v-axis />
	  	<v-legend />
	  	<v-line position="month*temperature" color="city" />
	  	<v-point position="month*temperature" color="city" :size="4" :v-style="style" :shape="'circle'" />
	</v-chart>
</template>

<script type="text/javascript">
	const DataSet = require('@antv/data-set');

	const sourceData = [
		{ month: 'Jan', Tokyo: 7.0, London: 3.9 },
		{ month: 'Feb', Tokyo: 6.9, London: 4.2 },
		{ month: 'Mar', Tokyo: 9.5, London: 5.7 },
		{ month: 'Apr', Tokyo: 14.5, London: 8.5 },
		{ month: 'May', Tokyo: 18.4, London: 11.9 },
		{ month: 'Jun', Tokyo: 21.5, London: 15.2 },
		{ month: 'Jul', Tokyo: 25.2, London: 17.0 },
		{ month: 'Aug', Tokyo: 26.5, London: 16.6 },
		{ month: 'Sep', Tokyo: 23.3, London: 14.2 },
		{ month: 'Oct', Tokyo: 18.3, London: 10.3 },
		{ month: 'Nov', Tokyo: 13.9, London: 6.6 },
		{ month: 'Dec', Tokyo: 9.6, London: 4.8 }
	];

	const dv = new DataSet.View().source(sourceData);
	dv.transform({
		type: 'fold',
	  	fields: ['Tokyo', 'London'],
	  	key: 'city',
	  	value: 'temperature',
	});
	const data = dv.rows;
	const scale = [{
		dataKey: 'month',
	  	min: 0,
	  	max: 1,
	}];
	export default {
		name:"",
		data(){
			return {
				data,
				scale,
				height: 400,
				style: { stroke: '#fff', lineWidth: 1 },
    		}
		}
	}
</script>